How DNA is Collected and Used
DNA
DNA can be obtained from almost any body fluid or tissue. It is obtained for analysis by crime scene examination, collecting a sample from a suspect - known as a Criminal Justice (CJ) sample - or by voluntary contribution.
The sample goes through various processes to extract the DNA before it is analysed and a profile made. A profile is a numerical representation of the DNA's unique properties.
After these processes, the profile is loaded onto the Scottish DNA database, and also exported to the UK National Database. After comparison with existing profiles, any matches between unsolved crime DNA profiles and suspect profiles are issued to Police Forces for investigation. These are know as "Intelligence Reports".
In Scotland, when someone is arrested and held in custody, the police have the power to require forensic samples from that person. In the case of a sample for DNA purposes, this is usually done by taking a swab of saliva from the inside of the mouth. This is known as a criminal justice (CJ) sample.
In Scotland, all profiles and samples from a suspect must be destroyed following the end of an investigation if it does not result in a conviction, however, there are some major exceptions to this.
One such exception is if the arrest is for a relevant violent or sexual offence and the accused was proceeded against but not convicted. In such cases, the profiles and sample can be kept for up to 3 years. After this period, the Chief Constable can then apply to a sheriff to keep the profiles and sample for up to two more years and this process can be repeated at the end of each extended period.
A relevant offer is not a conviction, and where an individual has been issued with a relevant offer as an alternative to prosecution for an offence, and one or more of the offences is a relevant sexual or violent offence, the profiles and sample can be kept for up to 3 years. After this period, the Chief Constable can then apply to a sheriff to keep the profiles and sample for up to two more years and this process can be repeated at the end of each extended period. If the offence is not a relevant sexual or violent one, the profiles and sample can be kept for up to 2 years with no possibility of extension.
In the case of a fixed penalty notice offence, which is also not a conviction, the retention period is a fixed two years. The retention period cannot be extended.
Another exception is for children referred to Children's Hearings which are civil proceedings and do not result in convictions. The Criminal Justice & Licensing (Scotland) Act 2010 introduced retention in cases of relevant sexual and violent offences where, if the child and their parent(s) has/have accepted the offence grounds or had them established in court. Data can be retained for 3 years with further extensions of up to 2 years subject to authorisation by the court. This applies to children aged eight years and above.
